Self-adjusting variable orifice spray nozzle



Dec. 4, 1962 R. E. BORN 3,066,871 SELF-ADJUSTING VARIABLE ORIFICE SPRAY NOZZLE Filed Aug. 18, 1961 2 Sheets-Sheet l Dec. 4, 1962 R. E. BORN 3,066,871

SELF-ADJUSTING VARIABLE ORIFICE SPRAY NOZZLE Filed Aug. 18, 1961 2 Sheets-Sheet 2 P/P/d)? H 7 H540 04 0/?IFICE 63 67/55 United States Patent Office 3,066,871 Patented Dec. 4, 1952 SELF-ADJUSTHYG VARIABLE GREECE SPRAY NOZZLE Robert E. Born, Broadview, iii, assignor to American Well Works, a corporation of iilinois Filed Aug. 18, 1961, Ser. No. 132,350 12 Claims. (6!. 239-254) This invention relates to a self-adjusting variable orifice spray nozzle and more particularly is concerned with providing such nozzles on a reaction driven rotary distributor of the type used for distributing sewage over trickling filter beds.

The aim of a reaction driven rotary distributor is to lay down a fine, even amount of liquid over a trickling filter bed. This is accomplished by letting the liquid flow into a rotary distributor and discharge itself through numerous spaced openings in the distributor arms. In flowing through these numerous arm openings a jet action is created which causes the distributor to rotate and pass over the entire area of the filter bed.

It is also desirable and necessary to spread the streams of liquid running out of the discharge openings. Otherwise, the filter bed will not be covered evenly and eventually deep furrows will be cut into the filter bed. in the prior art, a spreader plate (or some other device) is set in front of every discharge opening and as the stream of liquid leaves the opening it strikes against the plate. The size and quality of the spread is dependent upon the size of the discharge opening, the speed of the discharge and the angle that it strikes against the plate.

The amount of flow through a normal rotary distributor will vary throughout the day, the week, the month and the seasons. The size and number of discharge openings in a rotary distributor is one of the important governing factors in determining its capacity. if the dis charge openings are made large enough to accommodate the peak How then not enough hydraulic head will be built up at low ilow to have the speed and force necessary to create the jet action needed to rate the distributor, and to have the necessary satisfactory spread. If, on the other hand, the discharge openings are of the proper size for satisfactory operation at the minimum fiow, then at higher flows they would not let enough liquid flow through them; hydraulic head would build up and finally overflow and, of course, the capacity of the distributor would be reduced accordingly.

Reaction drive rotary distributors are produced with a minimum of two arms for balance and proper distribution. A two arm distributor can be used where the flow variation that is encountered is not greater than a ratio of 2:1. Where greater fiow variation exists it is the common practice to mount extra arms with overflow controls. These extra arms receive liquid only when the flow is greater than the two regular arms can handle.

The need for overflow arms and associated controls for handling fiow variations of greater than 2:1 leads to excessive installation costs.

The use of fixed orifice spray nozzles is known in the prior art but this greatly restricts the range of flow variation that can be handled. Even within their limited range of utility, these prior art nozzles do not provide an optimum spread of the spray discharge, with or without spreader plates; do not provide an efiicient jet action at low hydraulic head conditions due to the reverse forces created by the spray when striking the spreader plate; do not compensate so as to minimize the jet action created at high hydraulic head conditions; and do not inherently avoid clogging nor are they easy to clean and maintain.

The principal object of the prevent invention is to provide a self-adjusting variable orifice spray nozzle that is free of the above noted ditficulties.

Another object of the invention is to provide a reacticn driven rotary distributor equipped with a self-adjusting variable orifice spray nozzle to eliminate the need for costly overflow arms and related controls.

A more specific object of the invention is to provide a self-adjusting variable orifice spray nozzle arranged to produce a concentrated straight forward free spray discharge at low hydraulic head to maximize the jet action created at minimum flow conditions and to produce increased side flow spray discharge at higher hydraulic heads to limit the increase of the jet action that is created at higher fiow conditions.

A further specific object is to provide a self-adjusting variable orifice spray nozzle that automatically maintains a lower hydraulic head than the fixed orifice nozzles of the prior art.

Another object is to provide a spray nozzle construction that is less subject to becoming clogged by foreign material and that is easy to clean and maintain.

Other objects and advantages will become apparent during the course of the following description.

in the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a perspective view of a trickling filter bed and illustrates a reaction driven rotary distributor equipped with self-adjusting variable orifice spray nozzles in accordance with this invention;

FIG. 2 is an enlarged side elevational view of a nozzle and is taken in the plane of the line 22 of FIG. 1;

FIG. 3 is a plan view of the nozzle of FIG. 2;

FIG. 4 is a lengthwise horizontal sectional view through the nozzle of MG. 2 but illustrates it in an open relationship;

FIG. 5 is a reduced diagrammatic face view of a nozzle and illustrates its spray discharge pattern;

FIG. 6 is a graph of hydraulic head vs. orifice discharge rate of flow and illustrates the operating characteristics of the nozzle of the present invention in comparison with fixed orifice prior art nozzles; and

HG. 7 is a graph of hydraulic head vs. spray width for the nozzle of the present invention.

Referring now to the drawings and particularly to P16. 1, there is illustrated for purposes of illustrative disclosure, a trickling filter bed iii encased in a tank 11 that is equipped with a two arm reaction driven rotary distributor, designated generally at T2, for distributing sewage throughout the filter bed.

The distributor has a central riser 13 rotatably supporting a pair of radial distributor arms 14 each of which is equipped with a plurality of spray nozzles 15 leading generally laterally therefrom.

Sewage is supplied to the riser at its lower end (not shown) under variable hydraulic head pressure conditions, as determined by the particular sewage system. and passes through the distributor arms for discharge through the nozzles 15. The jet action of the sewage discharging through the nozzles 15 produces reaction forces for driving the rotary distributor.

In accordance with the present invention, self-adjustin" variable orifice spray nozzles 15 are mounted on the distributor arms and lead generally laterally therefrom to provide a substantially free flow spray discharge pattern to provide a uniform fine spray deposit that exhibits a maximum jet effect at low fiow rates and that becomes of progressively greater width at higher flow rates to retain the jet effect within acceptable limits.

In the preferred arrangement illustrated herein, the distributor arms 14 have side outlets 148 (FIG. 4) for direct mounting of the spray nozzles 15. Each nozzle comprises a nozzle tube 16 leading generally laterally from the distributor arm to terminate in a discharge opening 16D (FIG. 4) oriented in a plane facing generally upwardly at an oblique angle to horizontal and a weighted cover 17 swingably mounted across the nozzle opening to define jointly therewith a generally horizontally directed orifice leading through the lower region of the nozzle opening.

In FIGS. 2 to 4 the nozzle tube to is shown threaded directly into a side outlet of a distributor arm and it is provided with a rigid external boss 163 at a location adjacent the upper extremity of the nozzle opening. The weighted cover 17 has spaced parallel pivot arms 17A flanking the boss 16B and hingedly connected thereto by a pivot pin 18.

With this arrangement the cover normally spans the nozzle opening to lie in abutting relation to nozzle face portions bordering the nozzle opening. While the cover 17 may be arranged to block the entire nozzle opening, this can create problems due to freezing in the winter and it is preferred that the parts be arranged do that even when the cover is in fully closed position (see FIG. 2) there exists an initial orifice sized for the minimum flow of the distributor. In the illustrated arrangement the lower end of the nozzle face is bevelled or cut back from the plane of the nozzle opening as indicated at O to provide a clearance space between the nozzle and the cover and thereby define an orifice leading generally horizontally through the lower region of the nozzle opening.

In a typical application, the cover 17 is weighted so that it will not rise until a hydraulic head on the order of ten inches is built up but it is contemplated that an additional weight 19 may be mounted on the cover for suitable adjustment to permit the cover to rise at a higher or lower head as desired. The weight 19 is shown as an elongated block provided with a lengthwise slot. screw S extends through the slot and anchors the weight to the cover 17 at any selected position of adjustment.

In the preferred arrangement illustrated herein, a threequarter inch nozzle is employed and the nozzle opening 161) is oriented in a plane at an angle of 30 to the horizontal. A typical spray discharge pattern produced by the present nozzle is diagrammed in PEG. 5 wherein the letter W represents the width of the spray pattern as it reaches the trickling filter bed.

The graphs of FIGS. 6 and 7 illustrate the. performance characteristics of the self-adjusting variable spray nozzle of this invention. Curve 2t} in FIG. 6 represents the head vs. flow rate characteristic for the nozzle of this invention and illustrates that it can handle flow rates ranging from two gallons per minute up to as much as seventeen gallons per minute corresponding to a hydraulic head range of ten inches to forty inches. Performance curves for fixed orifice nozzles are shown at 21 and 22 and it will be apparent that the inch orifice of curve 21 can only handle flow rates ranging from two gallons per minute to six gallons per minute while the inch fixed orifice of curve 22 can only handle flow rates ranging from eight gallons per minute to eighteen gallons per minute. Obviously, the self-adjusting variable orifice nozzle of this invention accommodates a much greater range of flow variation than do the prior art nozzles and this makes it possible to eliminate need for overflow arms.

Curve 23 in FIG. 7 illustrates the width W of the spray discharge pattern for a range of hydraulic head pressures and shows that as the hydraulic head increases from ten inches up to about eighteen or twenty inches, the spray pat tern becomes progressively wider and reaches as much as 24 inches, substantially more than is possible in the prior art. This is explained because as the hydraulic Ihead increases and the weighted cover 17 begins to rise, the orifice which is defined between the cover 17 and the nozzle tube 16 opens increasingly more in the sidewise direction so that the spray discharge pattern becomes more fiat and becomes spread into a fine Wide spray.

As the hydraulic head increases even further up to, for

An attachment example, thirty inches, the momentum and speed of the stream being discharged tends to contract or narrow the discharge spray pattern. The normal design range for the illustrated equipment would contemplate a maximum hydraulic head of eighteen or twenty inches and up to this value the desired increase in pattern Width is provided. An important advance of the present design is that the nozzle can handle over-loads even though some narrow ing of the discharge spray pattern must be tolerated. The fixed orifice nozzles of the prior art, when loaded beyond their design range, cannot handle the over-load, a serious disadvantage.

For the variable orifice nozzle configuration represented by curve- 20 of FIG. 6, the flow rate at 10 inches of hydraulic head is 2.5 gallons per minute and at 20 inches of hydraulic head is 9.5 gallons per minute which represents a flow rate ratio of approximately 4:1 and distinguishes sharply from the fixed orifice curves 21 and 22 which have flow rate ratios on the order of 2:1 over this head pressure range of 10 inches to 20- inches.

The size of the cover 17 for the nozzle opening need only be great enough to permit the cover to contact the nozzle face portions bordering the sides and top of the nozzle opening. If the cover is made wider or longer, no appreciable change in the performance of the unit occurs. In the illustrated arrangement, the cover is formed with a substantially vertical lip at its lower end as this has been found to improve the spreading action that is obtained.

It should be understood that the description of the preferred form of the invention is for the purpose of complying with Section 112, Title 35, of the US. Code and that the claims should be construed as broadly as prior art will permit.

What is claimed is:

l. In a reaction driven rotary distributor for distributing" sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable over said bed and means on said arm including a selfadjusting variable orifice spray nozzle leading generally laterally from said arm to provide an orifice responsive to head pressure conditions thereat to discharge sewage from said arm in a free flow pattern that becomes progressively greater in volume and wider in span in response to greater head pressure to minimize increases in the reaction drive effect on said arm.

2. In a reaction driven rotary distributor for distributing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable over said bed, a spray nozzle having a discharge orifice leading generally laterally from said arm and means on said nozzle responsive to hydraulic head acting at said orifice for automatically adjusting the size of said orifice to accommodate a proportionally greater volume of flow when the hydraulic head acting at said orifice increases.

3. In a reaction driven rotary distributor for distribut-- ing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising agenerally horizontally extending distribution arm rotatable over said bed and means on said arm for discharging sewage therefrom and including a spray nozzle leading generally laterally from said arm and terminating in nozzle face portions bordering and defining a discharge opening oriented to face generally upwardly at an oblique angle to horizontal, a cover for overlying said discharge opening in substantially closed relation to nozzle face portions bordering side and top regions of said discharge opening and cooperable therewith to define an orifice directed generally lengthwise from said tube, means carried by said tube and engaged to said cover for mounting said cover for free swinging vertical movement about a horizontal axis extended transverse of said tube at a location above said nozzle and adjacent the upper region of said opening for accommodating automatic orifice varying movement of said cover in accordance with the weight dis tribution of said cover about said axis and the head pressure acting on liquid moving through said orifice.

4. In a reaction driven rotary distributor for distributing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable over said bed and means on said arm for discharging sewage therefrom and including a spray nozzle leading generally laterally from said arm and terminating in nozzle face portions bordering and defining a discharge opening oriented in a plane facing generally upwardly at an oblique angle to horizontal, a cover for overlying said discharge opening in abutting relation to nozzle face portions bordering side and top regions of said discharge opening and cooperable therewith to define an orifice directed generally lengthwise from said tube, means carried by said tube and engaged to said cover for mounting said cover for free swinging vertical movement about a horizontal axis extended transverse of said tube at a location above said nozzle and adjacent the upper region of said opening for accommodating automatic orifice varying movement of said cover in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid moving through said orifice.

5. In a reaction driven rotary distributor for distributing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable over said bed and means on said arm for discharging sewage therefrom and including a spray nozzle leading generally laterally from said arm and terminating in nozzle face portions bordering and defining a discharge opening oriented to face generally upwardly at an oblique angle to horizontal, a cover for overlying said discharge opening in substantially closed relation to nozzle face portions bordering side and top regions of said discharge opening and cooperable therewith to define an orifice directed generally lengthwise from said tube, means carried by said tube and engaged to said cover for mounting said cover for free swinging vertical movement about a horizontal axis extended transverse of said tube at a location above said nozzle and adjacent the upper region of said opening for accommodating automatic orifice varying movement of said cover in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid moving through said orifice with the elfective orifice that is defined by said tube and said cover opening progressively more and widening progressively more in proportion to progressive upward movement of the cover relative to the tube to distribute progressively greater flow in progressively wider span patterns and minimize increases in the reaction drive effect normally occasioned by such greater flow.

6. In a reaction driven rotary distributor for distributting sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable over said bed and means on said arm for discharging sewage therefrom and including a spray nozzle leading generally laterally from said arm and terminating in nozzle face portions bordering and defining a discharge opening oriented in a plane facing generally upwardly at an oblique angle to horizontal, a cover cooperably mounted in closure relation across top side and center regions only of said nozzle opening to define therewith a generally horizontally directed ever open orifice through the lower region of said opening, means mounting said cover for undergoing self adjusting orifice varying vertical swinging movement about a horizontal axis in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid to move it through said orifice, said axis extending transverse of said tube at a location thereabove and adjacent the region of said opening so that the effective orifice opens progressively more and widens progressively more in proportion to progressive upward movement of the cover relative to the tube to distribute progressively greater flow in a progressively wider pattern and minimize increases in the reaction drive effect normally occasioned by such greater flow.

7. In a reaction driven rotary distributor for distribut ing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable over said bed and means on said arm for discharging sewage therefrom and including a spray nozzle tube leading generally laterally from said arm and terminating in a discharge opening oriented in a plane facing generally upwardly at an oblique angle to horizontal, said tube having an external boss on its top side and adjacent the upper extremity of said opening, a cover cooperably mounted across said nozzle opening in abutting relation to nozzle portions bordering the side and top regions of said opening to define with said tube a generally horizontally directed orifice through the lower region of said opening, and means mounting said cover to said boss for vertical swinging pivotal movement about a horizontal axis through said boss to adjust the size of said nozzle in accordance with the weight of said cover and with the head pressure acting to flow sewage through said tube.

8. A self-adjusting variable orifice spray nozzle comprising a nozzle tube terminating in a discharge opening oriented in a plane facing generally upwardly at an oblique angle to horizontal, said tube having an external boss on its top and adjacent the upper extremity of said opening, a cover cooperably mounted across said nozzle opening in abutting relation to nozzle portions bordering the side and top regions of said opening to define with said tube a generally horizontally directed orifice through the lower region of said opening, and means mounting said cover to said boss for vertical free swinging pivotal movement about a horizontal axis through said boss to adjust the size of said orifice in accordance with the Weight of said cover and the head pressure acting on liquid moving through said opening.

9. In a reaction driven rotary distributor for distributing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distribution and comprising a generally horizontally extending distributor arm rotatable about a vertical axis through said bed and means on said arm for discharging sewage therefrom and including a generally horizontally directed nozzle tube leading laterally from said arm and defining a nozzle passage, said tube terminating in nozzle face portions bordering and defining a nozzle discharge opening lying generally in a plane having a normal directed forwardly and upwardly at an angle oblique to horizontal; a cover for overlying said discharge opening in substantially closed relation to nozzle face portions bordering the side and top regions of said discharge opening and cooperable therewith to define an ever open orifice within the lower region of said opening directed generally lengthwise from said tube; and means carried by said tube and engaged to said cover for mounting said cover for free swinging vertical movement about a horizontal axis extending transverse of said tube at a location above said passage and adjacent the upper region of said opening for accommodating automatic orifice varying movement of said cover in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid to move it through said orifice, with the effective orifice that is defined by said tube and said cover opening progressively more and widening progressively more in proportion to progressive upward movement of the cover relative to the tube to distribute progressively greater fiow in progressively wider span patterns and minimize increases in the reaction drive efiect normally occasioned by such greater fiow.

10. In a reaction driven rotary distributor for distributing sewage over filter beds, means for depositing spray on said bed at a rate related to head pressure conditions of the sewage supplied to said distributor and comprising a generally horizontally extending distributor arm rotatable about a vertical axis through said bed and means on said arm for discharging sewage therefrom and including a generally horizontally directed nozzle tube leading laterally from said arm and defining a nozzle passage, said tube terminating in nozzle face portions bordering and defining a nozzle discharge opening lying generally in a plane having a normal directed forwardly and upwardly at an angle oblique to horizontal; a cover for overlying, said discharge opening in substantially closed relation to nozzle face portions bordering the side and top regions of said discharge opening and cooperable therewith to define an orifice directed generally lengthwise from said tube; and means carried by said tube and engaged to said cover for mounting said cover for free swinging vertical. movement about a horizontal axis extending transverse: of said tube at a location above said passage and adjacent the upper region of said opening for accommodating auto-- matic orifice varying movement of said cover in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid to move it through said orifice, with the etfective orifice that is defined by said tube and said cover opening progressively more and widening progressively more in proportion to progressive upward movement of the cover relative to the tube to distribute progressively greater flow in progres sively wider span pattern and minimize increases in the reaction drive efiect normally occasioned by such greater tlow, with the weight distribution of the cover being arranged so that the cover remains closed in the presence of head pressures on the order of ten inches and is fully open in the presence of head pressures on the order of twenty inches with the Orifice having a flow rate ratio between cover open and cover closed positions on the order of 4:1. v

11. A self adjusting variable orifice spray nozzle comprising a generally horizontal nozzle tube defining a nozzle passage and terminating in nozzle face portions bordering and defining a nozzle discharge opening lying generally in a plane having a normal directed forwardly and seem.

verse of said tube at a location above said passage and. adjacent the upper region of said opening for accommodating automatic orifice varying movement of said cover in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid to move it through said orifice, with the eifective orifice that is defined by said tube and said cover opening progressively more and widening progressively more in proportion to progressive upward movement of the cover relative to the tube to distribute progressively greater flow in progressively Wider span patterns.

12. A self adjusting variable orifice spray nozzle comprising a generally horizontal nozzle tube defining a nozzle passage and terminating in nozzle face portions bordering and defining a nozzle discharge opening lying generally in a plane having a normal directed forwardly and upwardly at an angle oblique to horizontal; a cover for overlying said discharge opening in abutting relation only to nozzle face portions bordering the side and top regions of said discharge opening and cooperable therewith to define an ever open orifice Within the lower region of said opening and directed generally lengthwise from said tube; and means carried by said tube and engaged to said cover for mounting said cover for free swinging movement about a horizontal axis extending transverse of said tube at a location above said passage and adjacent the upper region of said opening for accommodating automatic orifice varying movement of said cover in accordance with the weight distribution of said cover about said axis and the head pressure acting on liquid to move it through said orifice, with the effective orifice that is defined by said tube and said cover opening progressively more and widening progressively more in proportion to progressive upward movement of the cover relative to the tube to distribute progressively greater flow in progressively wider span patterns.

References (Iited in the file of this patent UNITED STATES PATENTS 

